Separation of cobalt and nickel by liquid-liquid extraction from acid solutions

摘要

1,141,777. Cobalt and nickel extraction. ELDORADO MINING & REFINING Ltd. 17 June, 1966 [21 June, 1965], No. 27243/66. Heading C1A. Cobalt and nickel values are recovered from an acid lead solution by liquid-liquid separation using a salt of an organo-phosphoric acid compound of formula where R is H, substituted or unsubstituted alkyl, aryl or aralkyl, not more than one R being H and each R group other than H containing at least 8 C-atoms and the molecule containing at least 12 C-atoms, dissolved in a water-immiscible solvent. The leach solution is prepared by treating ore with nitric or sulphuric acid and removing elements such as Fe, As and particularly Cu by pH adjustment. The organo-phosphoric acid composed may be an alkali-metal or ammonium salt of di - (2 - ethylhexyl) phosphoric acid, heptadecylphosphoric acid, dodecylphosphoric acid, di- (1-methylheptyl) phosphoric acid, diisocytylphosphoric acid di - (2 - ethyl - 4 - methyl - pentyl) phosphoric acid, di - (2 - propyl - 4 - methyl - pentyl) phosphoric acid, octylphenylphosphoric acid, or the isooctyl or stearyl derivatives of alkyl acid phosphates. The compound is dissolved in toluene, carbon tetrachloride, benzene, chloroform, methylene chloride, 2- ethyl-hexanol, kerosene or naphtha to which either tributyl phosphate or isodecanol is added as an emulsion inhibitor. The cobaltloaded organic phase is separated from the aqueous phase and scrubbed with cobalt sulphate or nitrate, or dilute sulphuric or nitric acid to remove nickel before being stripped with sulphuric, nitric or hydrochloric acid to produce a cobalt salt. The nickel is recovered from the original raffinate by crystallization.